I don't see the problem here. They're adding value to their OS this way, value that will result in greater profits and therefore shareholder value. My MS stock is doing great thanks to moves like this!
If you don't like it, you don't have to use MS products.
Why do you doubt that? Even Microsoft, with all their money and NIH syndrome, are unlikely to invent a brand new application protocol just to serve ads.
ChromeOS puts Chrome in a nice safe sandbox (in addition to the sandboxing of Chrome tabs that happens on all OSes) that used selinux and other technologies. This requires modifications to Chrome. Replicating that for another browser might be harder than modifying ChromeOS to add something like this.
If you have to use it for work “whether you like it or not” then you’re extremely unlikely to have the permissions to install your own root certificate, which is a lot more sensitive operation than running Firefox.
Well then they’re able to install and run Firefox.
My point is the only situations where you have no control over browser installs are when the machine is locked down in such a way that you also cannot install root certificates.
Why not? Lots of services are now desktop apps and since you cannot run browser adblockers on Electron apps, this is the next best thing. I also run something similar on Android so I don't see ads in apps either, not just in the browser.
If other apps run into obscure errors due to ad blocking, then it's time to find alternative apps (pending overly-aggressive blocking causing the obscure error - which I have come across, although rarely).